1. Field of the Invention
The present invention relates to the surgical treatment of chondral defects and, more specifically, to a method and apparatus for autogenous transplantation of articular cartilage/bone cores in knees having chronic anterior cruciate ligament (ACL) deficiency, or isolated articular defects.
2. Description of the Related Art
Chronic ACL deficiency can result in a wide range of chondral damage, varying from superficial blemishes and fissures, to large, full-thickness defects. These lesions may also occur as isolated pathology in cruciate normal knees.
Chondral defects of the femoral condyles are widely recognized indications which comprise approximately 5% of all knees undergoing arthroscopy. Treatment, however, is difficult and controversial. In earlier known methods, meniscal pathology was treated, and the ACL was reconstructed, but the chondral lesion usually was left untreated. This approach leads to lesion enlargement and ultimately an advancing arthritic condition.
A protocol of arthroscopic osteochondral autograft transplantation for repairing chondral defects has been developed and tested in knees having chronic ACL deficiency by Vladimir Bobic, as reported in Arthroscopic Osteochondral Autograft Transplantation In ACL Reconstruction: A preliminary clinical study; Knee Surgery, Sports Traumatology Arthroscopy (1996), incorporated herein by reference.
The transplantation procedure, which is intended to prevent further joint degeneration and possible development of osteoarthrosis, involves selecting donor sites for osteochondral cores, capped with intact cartilage, prior to notchplasty. Donor sites are selected along the anterolateral and superior aspect of the notchplasty area, or on the superolateral and anterolateral aspect of the lateral femoral condyle in the non-weightbearing area above the sulcus terminalis. At the donor sites, multiple osteochondral cores 5 mm to 9 mm in diameter and 10 to 15 mm long, are harvested using tubular cutting instruments.
Recipient repair sites typically are located on the weightbearing area of the medial and lateral femoral condyles. Full-thickness chondral defects, typically larger than 10 mm in diameter, and up to 20 mm, are selected for treatment. Recipient sockets at the repair sites are prepared, and the donor cores are transferred and press-fitted into the recipient sockets.
The transplantation procedure described above has various difficulties associated with it. For example, removing the osteochondral cores from the tubular cutting instruments is difficult. In addition, improvements are needed in the formation of the donor cores and recipient sockets, especially to facilitate depth control during harvest as well as transplant insertion. In general, improvements are required in the instrumentation and techniques available to perform the transfer procedure.